function xstHipLenFn = stHipLenFn(x)
xstHipLenFn = sqrt(((1903*cos(x(1)))/5000 + (2261*cos(x(1) + x(2)))/5000)^2 +  ...
  ((-1903*sin(x(1)))/5000 - (2261*sin(x(1) + x(2)))/5000)^2) ...
;